80% Arms- Easy Jig

[00tec]

Picked up an "Easy Jig" from 80% Arms. Man this thing makes it simple. It's definitely one of the pricier jigs out there, but it's worth it in my opinion. You use a router to do the bulk of the work with a mill bit so you dont tear up your drill press spindle bearings. The jig has marked depth gauges so you can leave your calipers in your toolbox.

The jig only works with their lowers, but you can take a dremel to the side plates to fit other lowers. I have heard rumors of a universal jig in the works.

Overall, I like the purchase. The lowers themselves are nice and lightweight with a good finish. The jig sideplates, drill template, and mill template plates are coated, but, the router plate and spacer are not. I would prefer an "all or none" on the coating, but whatever. It would also be nice to have short pins pressed into the jig where it locates into the rear takedown hole. It currently uses a long bolt that goes completely through, so you have to be careful not to drill or mill through it. You take it out during 2 steps, but I could see that being a brain fart moment. The pins could be short enough to just insert in the hole, but not deep enough to be in the milling area. The threaded hole gets pretty clogged with chips during the process.
Overall, I have $150 in the jig, ~$40 in drill/mill bits and a drill stop. The router can be really any router with a 1/4 chuck. Took me like 2.5 hours on the first go, could probably be done in an hour or so if I wasn't taking my sweet time.
Lessons learned: Do this outside, it makes A LOT of aluminum splinters. Shop vac is not a bad idea. High rpm on the router gives a smoother finish.

A few photos of the process and end result are below.

[00tec]

[Wulf202]

If you use just any router wouldn't you put strain on the bearings if it's not a plunge router?

[Irving]

I was under the impression that routers rotate way too fast for this kind of work. I'm in absolutely no position to argue that point any further though.

[00tec]

If you use just any router wouldn't you put strain on the bearings if it's not a plunge router?

You use a drill (or drill press) to get do depth initially, the router is doing side cutting only. In other words, the tools are used within their design. I used a small harbor freight drill press and a Dewalt DWP611 compact router.

I was under the impression that routers rotate way too fast for this kind of work. I'm in absolutely no position to argue that point any further though.

It ran great at ~24k rpm using a 3 flute end mill.

[BuffCyclist]

I was under the impression that routers rotate way too fast for this kind of work. I'm in absolutely no position to argue that point any further though.

Speeds and feeds. You can apply these basic calculations for milling here. Lower will be 7075 or possibly 6061 alum. Pick your tool and determine the speed and you can calculate what size end mill you can use.

Or, spin as fast as possible and use TONS of lube.

Quick tip, if you're too cheap/lazy to buy real cutting fluid/oil, WD40 will work in a pinch.

[skullybones]

RPM Formula (12 * sfm) / (Pi * Diameter)

24K is perfectly within the limits of a ~1/4" Carbide Endmill in either series of aluminum. Lube is definitely preferred to help prevent galling between the Carbide tool and work-piece, but it will be messy with this setup. Check out tools with a ZRN Coating. They run great in Aluminum.
Use very light depth of cut to mitigate most galling. Blow out chips often as you create a variable chipload on your tool when they are re-cut.
If the tool dulls or chips, replace it.

Have fun! Keep your fingers attached.

[BuffCyclist]

RPM Formula (12 * sfm) / (Pi * Diameter)

24K is perfectly within the limits of a ~1/4" Carbide Endmill in either series of aluminum. Lube is definitely preferred to help prevent galling between the Carbide tool and work-piece, but it will be messy with this setup. Check out tools with a ZRN Coating. They run great in Aluminum.
Use very light depth of cut to mitigate most galling. Blow out chips often as you create a variable chipload on your tool when they are re-cut.
If the tool dulls or chips, replace it.

Have fun! Keep your fingers attached.

See, I knew if I just said speeds and feeds someone would come along and provide the formula for me because I was too lazy to write it out.

[ChunkyMonkey]

Good job, looks great

[smokeyradio]

Great review and nice work. I have been looking at getting one of these for
a few weeks, thanks for the review. I saw this one this morning and it is universal.

http://www.modulusarms.com/